Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Em qual rodada Roy Salvadori venceu a Classe D e Alan Hutcheson venceu a Classe B?
 ###Tabelas: CREATE TABLE multiple_medalists (multiple_medalists_id AUTO_INCREMENT PRIMARY KEY, Athlete (nation) VARCHAR, Olympics VARCHAR, Gold INT, Silver INT, Bronze INT, Total INT) CREATE TABLE residents_of_white_deer_park (residents_of_white_deer_park_id AUTO_INCREMENT PRIMARY KEY, Animal Name VARCHAR, Species VARCHAR, Books VARCHAR, TV Series VARCHAR, Gender VARCHAR, TV Seasons VARCHAR, Mate VARCHAR, First Appearance VARCHAR, Last Appearance VARCHAR) CREATE TABLE 2000–2009 (2000–2009_id AUTO_INCREMENT PRIMARY KEY, January VARCHAR, February VARCHAR, March VARCHAR, April VARCHAR, June VARCHAR, July VARCHAR, August VARCHAR, September VARCHAR, October VARCHAR, November VARCHAR, December VARCHAR) CREATE TABLE calendar__&__winners (calendar__&__winners_id AUTO_INCREMENT PRIMARY KEY, Round INT, Circuit VARCHAR, Date VARCHAR, Class A Winner VARCHAR, Class B Winner VARCHAR, Class C Winner VARCHAR, Class D Winner VARCHAR) CREATE TABLE ships_cruising_in_europe (ships_cruising_in_europe_id AUTO_INCREMENT PRIMARY KEY, Ship name VARCHAR, Year built/refurbished VARCHAR, Length VARCHAR, Crew INT, Guests INT, Staterooms INT, Comments VARCHAR)  
SELECT Round FROM calendar__&__winners WHERE Class D Winner = Roy Salvadori AND Class B Winner = Alan Hutcheson